Napoleon Online

[cannonmn]

This otherwise typical British bronze 3-pounder has been rifled at some point with 8 grooves and 8 lands. The rifling is not very deep indicating it was probably fired a good bit after being rifled. Who rifled the piece and why? What did the projectiles for it look like?

Details:

L: 42 in. nominal, 47 in. total.

Bore: 3 in. land-to-land.

Marks:

Monogram of MGO (Cornwallis?) on chase, monogram of George III on breech.

Weight mark: 2:2:15

Basering: F. Kinman 1796


The bronze barrel is presently mounted on a small naval carriage made of very dense hardwood, but I have no idea whether this is contemporary to the piece or much later. This piece belongs on a field carriage or galloper, so I am just assuming the naval carriage is an improper replacement.

Thanks in advance.

[Drouot]

this is a light common 3-pdr gun tube of 1778. calibre should be 2.9132inches. diameter of shot 2.775inches.

First Cypher is for the Marquis Cornwallis, master General of the Ordinance. MGO is short hand for this the second cypher is G III.

In 1792 French emigre Jacque Charles Manson appears to have left French service and came to Britain, he experimented with Rifled gun tubes for the horse artillery. This appears to what this gun tube should be, Never had confirmation this was done, evidentaly so if this 1796 tube was cast with rifling.

Fired roundshot attached the shot to a wooden sabot which fitted the rifiling. References I have are to a 6-pdr, buit evidentaly also used 3-pdrs.

[Blesson]

Drouot,

is there any proof that the rifles from this tube date from the period 1795?

Can we exclude a later modification? We know for example, that smooth bore muzzle loaders were transformed into rifled guns for experimental sake in the 19th century, 1850-60 say

LB

[cannonmn]

Thanks for the opinion. I guess I had been under the impression that this cannon barrel had been produced and issued as a regulation smoothbore 3-pounder of the model you mentioned, since the marks all comply with regulation for the smoothbore version.

I would think something would be different about the markings of this particular gun due to the fact that it could not use the same ammunition as the smoothbore, and would have different exterior ballistics.

Speculation aside, there's one precise method to check the theory you advanced. If the gun had been produced originally with the rifling it now has, the weight mark 2:2:15 would reflect its current weight fairly exactly, certainly within a pound. If the bore was reamed out slightly and the rifling cut into it at some date after the gun was originally issued, the weight would be significantly less than the marked weight, by at least some few pounds if not ten or more, I'd guess.

I will find a scale with the weight capacity required and weigh the gun within the next few days, and report back.

If my math is correct, the CWT mark of "2:2:15" works out to

112 x 2 = 224

28 x 2 = 56

15 x 1 = +15
____________

total 295 lbs.

Thank you for presenting the interesting possibility that I had never considered.

[Drouot]

Blesson,

tests weree carried out on orders of the Master General of the Ordinance the Duke of Richmond at his private estate at Goodwood.

tests were carried out using plain and rifled 6-pds of 10cwt. The rifling had 16 grooves(spirals)

If Ezekial bakers technology was used it was possible to cut a rifling into a smooth bore, but the technology was for hunting rifles. Britain at the time did not have a mechanised gun boring machine, the guns were still cast around a core and then bored out by hand to diameter.

The light common 3-pdr is not listed as being in service in 1813. Also the british gun tubes had a wear out period of just 300rounds before being replaced, so it would be suspect cutting rifling into a worn out gun tube in the 1850's especially a gun that had not been in service for 30yrs.

It does appear that Rifled guns were used to some extent by the British in the Napoleonic epoch. Likewise breach loaders were also experimented with in England and France.

[Drouot]

the rifling looks cast in rather than cut to me. Its very soft (worn I suspect), but also their are casting marks on the top and bottom of the grooves and lands.

Ahhhh. English weight and measure is different to American, so a modern weighing of the gun tube will produce a different weight due to lack of common weight and measure. so any new weight will need converting to the Imperial System.

2.2.15 matches the recorded regulation for this piece.

The shot used is the same as for the other 3-pdrs in use, just with a larger sabot which gripped the rifling according to the 1792 tests carried out for the Board of Ordinance.

[cannonmn]

>a modern weighing of the gun tube will produce a different weight due to lack of common weight and measure. so any new weight will need converting to the Imperial System.

I was under the impression that the pounds we use in the US are the same as those used in England, since they came from that country, but I could be wrong.

>Britain at the time did not have a mechanised gun boring machine, the guns were still cast around a core and then bored out by hand to diameter.

That's a bit different from what I'd read. I think I recall Muller having written that gun tubes were pretty much all (in UK and Europe anyway) cast solid and drilled after about 1780. Many cannon books reproduce a famous drawing of a waterwheel-powered vertical gang-boring machine with five or so cannon tubes being bored simultaneously, that's supposed to have been in use during the period we're discussing. That innovation may have been Swiss, I have to check, but it spread very quickly thoughout industrial countries. I'll double check some sources.

[cannonmn]

Here's something about cannon boring:

http://www.makingthemodernworld.org.uk/stories/manufacture_by_machine/03.ST.01/?scene=3

I can't recall their titles, but the Verbruggens were brought to England to be, what, the "master founders" at Woolwich, when, 1770's or 80's?

[Drouot]

The cannon boring machine is Swiss invented by jean Martiz. the first drill was erected in France in 1727, and used to produce the new guns of Valliere system of 1732, machines were erected at Douai and two at Strasbourg. By 1744 nine machines were erected in France. The technology was developed for iron guns in 1751 when Naval guns became bored and were set up at Rochefort, Brest, Toulon and other naval depots.

The cannon broing machine did not spread quickly through Europe. Austria had a version from 1753/4 ( a full 20yrs after France!), Russia 1786/7, Bavaria 1805, Prussia 1809+, Wurtemberg 1809. The russian machines were exptored from England after an act of parliament was passed to allow top secret machinery to leave the country. Bavarias machines were moved from Vienna in 1805 after its fall to the French. America got the cannon boring machine after 1809.

The Verbruggens worked for Joseph Berenger in France, son in law of Jean Maritz, and then came to britain after causing a scandal in France. The verbruggens machine is handpowered or donkey powered. The drill in Woolwich was not water powered. Woolwhich lacks the fundamental source of power for water wheel, a river.

Also Woolwhich was the sole foundry for brass guns, though on occaision some sub contractors were used to cast the guns, but were finished at woolwhich on the topsecret boring machine. The machine did one tube at a time and their was it appears only one. Also their was only one furnace to melt bronze till 1790's, and it took 2 weeks to make a gun tube. france about 72hours.

The print of the 5 cannon drills operating at the same time is from the often qouted Louis Toussard and is only applicable for France and after c.1755.

Which Muller is writing? Johan Muller in 1757 or Muller in the 1820's. Muller in the 1820's makes very sweeping statements that are often wrong. Anyhow by the 1820's and 30's britain did have a powered drill, but not in the Napoleonic epoch. Muller in 1757 is writing before the Verburggens came in the 1770's so his guns were cast on a core.

As far as I am aware American pounds use Centiles, so is broken into 10 and imperial into 12. Hence a translation of Adye by M G Mckenna 2004 in the Nafziger series is of little use in England as the imperial measure has been converted into american so a 12cwt gun tube has become 1800lb

I would write more but I want my book to say somthing new that has not been posted here already

[cannonmn]

Thank for the info, although I don't understand the discussion of weights at all, I'm afraid. As far as I can tell, the US still uses the same system of weights it inherited from Great Britain when it was a British colony.

There's some good prime-source info on production of bronze cannon at Woolwich during the late 18th C., cited in the book EIGHTEENTH CENTURY GUNFOUNDING, BY Melvyn H. Jackson and Carel de Beer, Smithsonian Institution Press, Washington DC 1974.

The book says that when the Verbruggens took over in the early 1770's, they overhauled the foundry at Woolwich and installed one large and one medium boring machine, to bore guns from solid castings. They later installed a small boring machine (the 3rd one) to bore coehorns, 3 pounders, etc.

One particular quote is interesting: (pp. 46)

The King's visit (to Woolwich) was reported by the Historical Chronicle of the Gentleman's Magazine of August 1773:

[cannonmn]

I weighed the tube on an accurate, recently calibrated non-spring shipping scale today, and the weight is 279.5 pounds.

In previous posts, I mentioned that the weight marked under the cascabel of the tube is "2:2:15" which works out to 295 pounds, so the tube has "lost" 15.5 pounds somewhere along the way.

The most likely explanation is that the weight was reduced when the tube was rifled, which necessitated shaving out enough bronze to form the grooves that we now see in the bore.

A very rough check could be done by calculating the volume of the bronze that had been where the grooves now are, then multiplying by the density of gunmetal bronze (specific gravity is often listed as 8.7 for this alloy.)

[Drouot]

yes I have the same book from the smithsonian. The three boring machines were still donkey or man powered. Prints from 1820 shew the trunnions being finished by hand and other exteranal surfaces.
Still 3 mancines for an entire country seem incredibly small provision, when France had 10 or so foundrys each with 6 drill machines, some having more than one machine. Most of these were waterpowered.

I agree it does look very likely that the rifling was cut in afterwards and post the initial weighing of the tube. Of course dating when this occured is problematical. We know that Manson/Manton was working with rifled cannon 1790-1800, so the rifling could have been new to the gun tube.

[cannonmn]

Thanks Drouot for the information. Incidentally we plan to fire this tube before too long. The 3-pounder's trunnions are a good fit for the steel field carriage of the 7CM rifled breechloading Skoda gun of ca. 1880

We're casting soft lead projectiles with hollow bases which will expand into the rifling upon firing. This method is being used successfully by many muzzle-loading rifled cannon shooters in the US. Although the projectiles we'll use are not authentic, our goal is to punch holes in the center of a plywood target, and the lead projectiles will do that.

[cannonmn]

We are firing the cannon with 7-pound hollow-base lead projectiles and a minimum of 6 ounces of black gunpowder. The lead projectiles squeeze into the rifling and spin up properly, showing no yaw upon entering the plywood target. Will post photos soon.

[cannonmn]

pictures